cpu issues?

when i run my first person shooter, with 10 animated characters, my cpu is 99%.
when i run 1 animated character, my cpu is 85%…
is this a problem?

i dont want to overload my system, everything is running fine in the game itself, but my fan starts whirring and i note the cpu usage…

should i increase my ram?

my machine specs are:
Macbook 10.4.1
Processor 2 GHz Intel Core 2 Duo
Memory 1 GB 667 MHz DDR2 SDRAM
SMC Version 1.13f3

see eric’s post http://forum.unity3d.com/viewtopic.php?p=111015#111015